Virtual reality (VR) technologies and relevant applications are currently developing expeditiously. Panoramic video is an important component in AIR technologies. Because the panoramic video records a whole footage in a 360° angle of view, it has an extremely large data size; therefore, compression of the panoramic video is a key technology in VR applications.
As mentioned above, the panoramic video records a whole footage in a 360° angle of view; however, an individual user can only view part of the panoramic video footage at a same time point. Conventional coding methods would indiscriminately code, with the same or similar quality, different regions of the panoramic video image into one code stream for transmission, which thus have very large redundancies. One feasible approach of removing the redundancies is to generate a plurality of code streams for coding the panoramic video, wherein different code streams focus on coding of different regions (i.e., regions of interest) of the panoramic video footage; and an individual code stream only codes the region of its own interest at a high quality and a high code rate, but codes other regions (Non-ROIs) at a low quality and a low code rate. According to this method, the individual code stream has a code rate far lower than a code stream has in the conventional coding methods but may still maintain a same coding quality for the region of its own interest, which greatly reduces the overhead of panoramic video transmission. However, existing description methods are inefficient, which cannot satisfy the requirements of effectively describing panoramic video ROIs and thus cannot correspondingly code the same.